• Atmosphere
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• v.20 no.4
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• pp.519-530
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• 2010

In this paper we review current research on Atmospheric Brown Clouds (ABCs) with lightweight Unmanned Aerial Vehicles (UAVs) and miniaturized instruments. The UAV technology for in-situ measurements, including aerosol concentration, aerosol size distribution, aerosol absorption, cloud drop size distribution, solar radiation fluxes (visible and broadband), and spectral radiative fluxes, is a leading-edge technology for cost-effective atmospheric sounding, which can fill the gap between the ground measurement and satellite observation. The first experimental observation with UAVs in Korea, Cheju ABC Plume Monsoon Experiment (CAPMEX), conducted during summer 2008 revealed that the Beijing plumes exerted a strong positive influence on the net warming and fossil-fuel-dominated black-carbon plumes were approximately 100% more efficient warming agents than biomass-burning-dominated plumes. Long-term sustainable routine UAV measurements will eventually provide truly three-dimensional data of ABCs, which is necessary for the better understanding of their climate impacts and for the improvement of numerical models for air pollution, weather forecast and climate change.

• Journal of Distribution Science
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• v.22 no.2
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• pp.51-61
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• 2024

Purpose: This comprehensive study delves into the intricate relationship between customer engagement, perceived risk, and perceived value within China's burgeoning e-commerce livestreaming sector. It focuses on how different customer engagement types in livestreaming influence their perception of value and risk. Research Design, Data, and Methodology: Adopting a convenience sampling approach, this research scrutinizes data collected from 852 consumers actively involved in e-commerce livestreaming shopping. Participants provided their insights through a meticulously designed questionnaire survey. Structural equation modeling helped examine the interplay between customer engagement, perceived risk, and value. Results: Significant impacts of customer engagement on perceived value and risk were found. Observation-based, conversation-based, and action-based engagements enhance perceived risk, while conversation-based and action-based engagement reduce perceived risk. Interestingly, observation-based engagement did not significantly affect perceived risk. The study also uncovered that perceived risk negatively impacts perceived value. Conclusions: The research offers insights into customer behavior and value creation in e-commerce livestreaming. It underscores how different engagement types affect perceived value and risk, aiding e-commerce platforms and businesses in strategy development to improve customer experience and minimize risks, enhancing perceived value in this dynamic sector. Enhances understanding of customer engagement dynamics in China's e-commerce livestreaming, guiding strategic development.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.53.3-54
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• 2018

Solar Proton Events (SPEs) are the energetic phenomena related particle acceleration occurred in solar corona. Conventionally, they have been classified into two groups as the impulsive and gradual cases caused by reconnection in the flaring site and by shock generated by CME, respectively. In the previous studies, we classified these into four groups by analyzing the proton acceleration patterns in multi-energy channel observation. This showed that acceleration due to the magnetic reconnection may occur in the corona region relatively higher than the flaring site. In this study, we analyzes 54 SPEs observed in the energy band over 25 MeV from 2009 to 2013, where STEREO observations as well as SOHO can be utilized. From the multi-positional observation, we determine the exact time at which the Sun-Earth magnetic field line meets the CME shock structure by considering 3-dimensional structure of CME. Also, we determine the path length by considering the solar wind velocity for each event, so that the SPE onset time near the sun is obtained more accurately. Based on this study, we can get a more understanding of the correlation between CME progression and proton acceleration in the solar coronal region.

• Korean Journal of Veterinary Research
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• v.59 no.1
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• pp.17-24
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• 2019

Animal models of osteoarthritis (OA) have played a key role in understanding the etiology of OA and in the development of new therapeutic strategies. Although pigs have an advantage as an animal disease model due to their similarity to humans, there are few studies on the induction of OA in minipigs. Therefore, this study aimed to characterize disease progression of OA in total medial meniscectomy (TMM)-operated skeletally mature minipigs, up to day 180 postoperatively. There were no significant alterations in vital signs or hematological indices throughout the observation period. However, clinical manifestations of OA in the medial femoral condyles of TMM-operated minipigs were progressive, depending on postoperative duration, with respect to osteophytes formation and roughened surfaces on radiological observation, cartilage erosion under macroscopic examination, and severe cartilage defects including fibrillation, vertical fissures, and cartilage denuding on histopathological observation, with the highest score indicating late-stage OA on day 180 and without indicating apparent variation between subjects. In particular, the lateral femoral condyles were also degenerated, possibly due to localization of weight-bearing from both menisci to the lateral meniscus. Therefore, TMM in minipigs is suitable for reproducible induction of degenerative changes in the femorotibial joints that closely resemble late-stage OA, and is suitable for use in further research.

• Geomechanics and Engineering
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• v.22 no.1
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• pp.1-9
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• 2020

This paper presents an investigation of the ground response of a gob-side gateroad suffering mining stress induced by a 21 m-thick coal seam extraction. A field observation, including entry convergence and stress changes monitoring, was first conducted in the tailgate 8209. The observation results of entry convergence showed that, during the adjacent panel 8210 retreating period, the deformation of the gob-side gateroad experienced a continuous increase stage, subsequently, an accelerating increase stage, and finally, a slow increase stage. However, strong ground response, including roof bending deflection, rib extrusion and floor heave, occurred during the current panel 8209 retreating period, and the maximum floor heave reached 1530 mm. The stress changes within coal mass of the two ribs demonstrated that the gateroad was always located in the stress concentrated area, which responsible for the strong response of the tailgate 8209. Subsequently, a hydraulic fracture technique was proposed to pre-fracture the two hard roofs above the tailgate 8209, thus decreasing the induced disturbance on the tailgate. The validity of the above roof treatment was verified via field application. The finding of this study could be a reference for understanding the stability control of the gob-side gateroad in extra thick coal seams mining.

• Journal of the Korean Solar Energy Society
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• v.32 no.4
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• pp.71-81
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• 2012

This study for the understanding of the radiation environment according to the altitude in urban area in the summer observes the long and short wave radiation environment at the 4 urban areas with different height and the 1 suburban area. The results of this study are as follows. (1) When the altitude was high, the more short wave radiation was observed. (2) As the altitude was high, the temperature of atmosphere got lower. And because of that the downward long wave radiation was also lower. This general trend was confirmed through the study. (3) Through the observation of long wave radiation, the upper atmosphere of suburban area had the atmosphere characteristic which the temperature was rising and decreasing faster. Therefore, the difference radiation characteristics between the urban and suburban area were confirmed. (4) The result of the ratio of short wave radiation to long wave radiation(short wave radiation/long wave radiation) according to the altitude and location, the value was increased when the distance was far from the artificiality structure or a heat source, and the urban effect became smaller. Thus, it is expected that the ratio will be an evaluation index for evaluating urbanization effect.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.5
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• pp.89-97
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• 2002

This report describes the first prize design of Midongsan Eco-park, which is located in Chungcheongbuk-do (North Chungcheong) province. Criteria of the winning design are as follows: 1) The design should include a neighborhood park as well as a portion of a green zone, in order to harmonize the area ecosystem, gradually assimilate the surroundings, and serve as an education tool for the public. 2) According to an analysis of area maps and a site-inspection, a preserved area, a buffer area, a restored area, and a developed area should be developed. In the buffer and restored areas, major facilities and activity spaces should be set up. 3) Observation trails should be accessible to visitors, and a variety of adventure programs should be available. 4) The eco-park should be designed to provide a habitat for the Gorani (Chinese water deer) which used to live around Midongsan. 5) For sensuous and vivid visitor experiences, diverse programs are to be designed to accommodate different seasons, visitor ages, and required time. Environment and eco-education are to be emphasized to maximize the effect of the eco-programs. 6) Optimal activities for visitors of different ages, optimal time intervals and eco-programs by age are also suggested. 7) Facilities are zoned into three sections according to level of development. Each section has a main area and supplementary areas for better understanding. 8) Nature-friendly arrangement of facilities and construction should minimize earthwork and adverse effects on the local ecology. Throughout the planning, the following things were learned: longer-term analysis including all season's observation is essential; planning, designing, bui Iding and managing should be based on this careful, extended observation. The contest should have taken plate over a longer period of time in order enable more detailed planing of the eco-park For improved management and activities, a volunteer system in linked with schools eco-institutions and NGOs should be developed with eco-interpreters.

• Atmosphere
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• v.26 no.4
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• pp.673-686
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• 2016

Understanding limitation of simulation for Planetary Boundary Layer (PBL) height in mesoscale meteorological model is important for accurate meteorological variable and diffusion of air pollution. This study examined the accuracy for simulated PBL heights using two different PBL schemes (MYJ, YSU) in Weather Research and Forecasting (WRF) model during the radiosonde observation period. The simulated PBL height were verified using atmospheric sounding data obtained from radiosonde observations that were conducted during 5 months from August to December 2014 over the Gumi weir in Nakdong river. Four Dimensional Data Assimilation (FDDA) using radiosonde observation data were conducted to reduce error of PBL height in WRF model. The assessment result of PBL height showed that RMSE with YSU scheme were lower than that with MYJ scheme in the day and night time, respectively. Especially, the WRF model with YSU scheme produced lower PBL height than with the MYJ scheme during night time. The YSU scheme showed lower RMSE than the MYJ scheme on sunny, cloudy and rainy day, too. The experiment result of FDDA showed that PBL height error were reduced by FDDA and PBL height at the nudging coefficient of $3.0{\times}10^{-1}$ (YSU_FDDA_2) were similar to observation compared to the nudging coefficient of $3.0{\times}10^{-4}$ (YSU_FDDA_1).

• Journal of Korean Elementary Science Education
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• v.32 no.3
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• pp.327-345
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• 2013

This study aims to investigate how pre-service elementary school teachers understand 'something scientific', 'being scientific', 'scientific events' and 'scientific questions' through semantic network analysis. To achieve this purpose, this study carried out a central analysis of the frequency and density of words and the degree of connection between key words, a concentric analysis, a click analysis and a common network analysis through text semantic network analysis by using NetMiner 4.0 Program. Based on the results of these analyses, this study came to the following conclusions. Firstly, in perceiving 'something scientific', pre-service elementary school teachers recognized 'verification', 'objective' and 'experiment' as most important words. In other words, they perceived that main grounds for something scientific should be provided through clear facts, possible to be verified and accompanied by an exact and logical theoretical system. In regard to 'being scientific', they perceived 'explanation', 'objective' and 'verification' as most important words, while having a traditional point of view that science is a set that can be explained objectively. Secondly, in regard that the term, 'observation', is contained in 'scientific events', they showed a high rate of understanding it as a scientific event. In regard to scientifical reasons, they showed the highest frequency of 'observation', and for unscientific reasons, they showed the highest frequency of 'behavior'. In perceiving 'scientific questions', they showed the highest frequency of determining bacteria-related questions as scientific. As a reason why they thought as scientific, they mentioned 'observation' most frequently like 'scientific events', while mentioning 'value judgement' as a reason why they thought as unscientific most frequently. From the results of integrated network analysis, this study found out that words pre-service teachers commonly used in stating scientific events or scientific questions were overlapped with words they mentioned for scientific events or scientific questions. As a result, it was found there were many pre-service teachers having interpreted scientific words without clearly distinguishing scientific events or scientific questions.

• Journal of the Korean earth science society
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• v.32 no.5
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• pp.514-520
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• 2011

As homework, a total of 32 seventh grade science-gifted students were asked to observe the moon at daily intervals for one month duration. They were also asked to take the photos and to record relevant variables in a given format. The purpose of the task was to investigate what students thought, as they observed the moon. The results show that students paid attention mainly to the position of the moon relative to other variables such as the date in the lunar calendar, the observer's position on the earth, and the position of the sun. Overall students' response implied that students did not observe the lunar phase in relation with relevant variables. Some reponses from students show common misconceptions such as the cause of the lunar phase to reflect the shadow of the earth. However, some responses reveal students' idea that has been rarely reported in the previous researches. For example, some students drew the moon to revolve in the opposite direction. Significant number of students drew the sun's position to be due west before the full moon and due east after the full moon. Few students recognized the relation between the time of observation and observer's position on the earth. The results of current research suggest that not only the education but also the research needs to be expanded to consider informal environment such as the actual field conditions.